Optical Disk Storage Options

DVD-ROM

‘DVD-ROM’ stands for Digital Versatile Disc (Or sometimes ‘Digital Video Disc) Read-Only Memory. This is a type of optical disk invented and developed in 1995, and offers higher data storage capacity than CD types.

Like CD-ROM, DVD-ROMs can only be read by computers or DVD players and cannot be erased or rewritten. Standard DVDs are 120 millimeters in diameter and look very similar to a CD, however they are able to hold up to 4.7 GB of data in single-sided, single-layer disks. DVDs can be dual-sided, allowing the data storage capacity to be increased to up to 9.4 GB.

Blu-Ray

Blu-Ray discs are the industry successor to the DVD format, and are capable of storing a great deal more data on disk. ‘Blu-Ray’ refers to the blue laser used to read the disk, which is different to the typical red-laser used in older formats. Since blue lasers have shorter wavelengths, more information can be read in a shorter period of time, allowing data such as high-definition video and audio to be stored and read back easily.

Blu-Ray discs are able to store up to 25 GB of data per layer, with dual layer discs being the typical industry standard, allowing 50 GB of data to be held. Blu-Ray competed with the HD-DVD format when it originated in 2006-2008, however the creators of the HD-DVD conceded in 2008, admitting that the Blu-Ray was cheaper and allowed for more secure and protected data storage.